By Alliriyan, who does not own Harry Potter

QUACK!

On a rare, hot day, some of the Gryffindors were almost glad to be in the Potions dungeon. The pervading chill was soothing to their sunburnt noses and baking bodies. But Neville would never be happy to have Potions. Any subject that involved him being shut in a small room with malevolent Professor Snape and forced to slice, dice and peel endless numbers of bizarre ingredients was not destined to make him happy.

They were making Purging Potions today. Not the most tasteful of topics, but a Purging Potion was guaranteed to wash out any minor illnesses, ailments or food poisoning that might be causing sickness. The creation looked just as messy as the end effect sounded…

Across the room Malfoy and his cronies were muttering over their cauldron, probably wondering how to spike Potter's drink with something so noticeable without being caught. Theirs was pale blue with the consistency of heavy oil. At the table in front of Neville, Hermione was failing to hide her anger as Snape spooned up a quantity of her electric blue, sparkling brew and let it fall back into the cauldron with a sneer.

"Too much fizz, Miss Granger. A textbook example, however the textbook is not infallible. Did it not occur to your similarly fallible logic that such a fizzy potion cannot be swallowed? Either find some way to lose half of that fizz, Miss Granger, or lose your top spot in the class." He raised his voice to address the rest of the room. "You have twelve minutes to complete your cack-handed concoctions and hand them in to me."

Neville gawked helplessly at the vile-smelling, sunshine-yellow stodge congealing under his gaze. He threw a handful of Puffapod Beans in and poked it with a long wooden spoon. The pink beans vaporised upon contact and when he lifted out the spoon it was a lot shorter. Then, horror of inevitable horrors; the large, aquiline nose of Professor Severus Snape inched into his vision.

"What," drawled the insufferable teacher with slow delight; "have you done, Longbottom? The only purging this will manage would be to purge the drinker from the face of the planet. Your grandmother must be tiring of replacing your potions equipment by now, surely. We can only count ourselves lucky that it doesn't seem to affect the pewter of the cauldron."

He paused for dramatic effect. "Longbottom, you don't need to cement your infamy by being the first person to melt the solid stone of the Potions floor – the entire school is already well aware of your idiocy. Three ounces of Jarvey fur to be sprinkled on top, Longbottom, to prevent the caustic properties. Take it from the school stores. And then we shall feed it to your toad and discover what you have created."

Neville voiced a low moan of despair which utterly failed to move Snape. He trudged to the cupboard. He measured out three ounces of Jarvey fur. He sprinkled them morosely onto the most corrosive substance known to man. They singed, releasing a sound like the jabber of insults. Neville folded them into the mess with the stub of his spoon. He tried to, at least, but the stuff had gone rock solid. He poured on a jug-full of water, which he had previously spilt fairy dust in.

Every person in the classroom choked when clouds of steam billowed out of the cauldron. Snape looked tempted to evacuate the dungeon and sort out Longbottom's disaster himself. Burning with shame, Neville stared at his desk and looked no one in the eye. He didn't notice that the fairy dust in the smoke had coated the room. Gregory Goyle was bobbing around the ceiling and even dark, dastardly Snape was sparkling.

"Longbottom," ground out the Head of Slytherin, furiously. He loomed over the stupid student with murder in his eyes. "Give me your toad."

Gulping, Neville placed Trevor in the glitter-spangled hands of his greatest fear. Producing a golden spoon from a hidden pocket, Snape scooped up a portion of the sulphur-yellow goo and forced it down the wriggling amphibian's throat.

There was a hushed silence. No one breathed. Neville face was an essay on terror.

Trevor swallowed.

Trevor blinked.

Trevor opened his mouth wide, and then –

Trevor quacked.

There was an explosion of bewildered mutters. The toad sprang from Severus's grip and made the 489th escape attempt of his life, quacking all the way.

In an attempt to regain control of the class, Snape analysed the potion's effects.

"Congratulations, Longbottom, you have managed to transfigure your toad's voice box into that of a duck. I believe that deserves a 'T'."

"T?" squeaked Neville.

"T for Troll. A grade reserved for extremely spectacular failures. I expect you'll be seeing it a lot as you go through life." Snarked the greasy-haired teacher nastily. He turned to Neville's charred cauldron and swished his wand.

"Evanesco." He commanded off-handedly.

Something backfired and the entire desk; cauldron, potion, and all detonated in an instant. The explosion rocked the dungeon, throwing the Gryffindors and Slytherins against the wall in a bickering heap. Yellow, brimstone-stinking smog hung in the air and Snape had vanished.

Neville was the first to move. He was a little braver with Snape out of sight.

"You blew up Snape!" squawked Pansy Parkinson.

"Yay!" ventured Ron quietly, in case Snape was behind the debris. Hermione darted towards the overturned cauldron and its massive dent. "Help me lift it Neville!" she urged. He hurried to comply.

Together they rolled it onto its side. Where it had once stood, staring sweetly up at them with beady black eyes, tiny and downy; was a duckling. It began to tell them off, making heated quot-quot-quot-quot noises.

"Is that…Snape?" queried Harry, eyes wide in amazement.

The fluffy yellow duckling quacked even louder. When the student body cracked up as one, it sped towards the door in a high-speed waddle amid howls of laughter. However each step was so small it took about five minutes to get there. Sides splitting, Gryffindors and Slytherins followed the transfigured Potion Master with wide grins. Snape made it all the way to the stairs before he was stumped by the height of the obstacle.

"Think we should help him?" asked Seamus. The class sniggered. Draco Malfoy was shoved to the front of the twenty-strong crowd, protesting all the way.

"You're his favourite, you have to pick him up!" laughed Hermione, for once not fretting over rules. He'd done it to himself, after all.

"He doesn't have favourites! If I pick him up he'll expel me!" snapped Draco, sobering quite quickly.

"Oh, we'll miss you so, Draco;" pouted Lavender soulfully, adding, "Snape looks quite sweet as a duckling, can't we keep him?"

Harry and Ron were crying with laughter. "Ah, my ribs ache!" cackled Ron.

When Goyle approached from behind, still floating three feet off the ground, all decorum was promptly lost. Eventually Malfoy was bullied into scooping up the hysterical Snapeling, and they carried him to Dumbledore's office.

Once they reached the gargoyle guarding the Headmaster's headquarters, the score of teenagers milled about trying to guess the password.

"It'll be some kind of sweet," Harry told them, "Sherbet Lemon!"

"Fizzing Whizbees!"

"Chocolate Frog!"

"Cockroach Cluster, Sugar Quills, liquorice wands, Blood Pops, Pepper Imps!"

"Gobstoppers, humbugs, mints, jelly snakes!" chanted a Muggleborn named Leanne.

"What are they?" asked Crabbe.

"Turkish Delight!" added the girl. The gargoyle cracked its wings and hopped to one side with a wide grin.

"What's Turkish Delight?" whined Crabbe.

He was interrupted by Draco's yell as the duck bit him for the umpteenth time.

At last, the pack of them trooped up the spiral elevator and crowded into Dumbledore's office. As usual, Albus Dumbledore gazed at them without a speck of shock as though he'd been expecting them all term and why were they late? For once, though, his expression twitched a little upon the sight of Snape the Ugly Duckling.

When Snape was dropped unceremoniously on the desk by an irritated, bruised Malfoy; Dumbledore bent down to the same level and peered at his former employee through his half-moon spectacles.

"Oh, dear, Severus, what has happened to you?" he murmured in an admirably steady voice. It took all his people skills not to laugh.

The little yellow duckling quacked a few choice insults guaranteed to give complexes to anyone if only they weren't in Duck.

"That's not very nice, Severus, the students inform me you did this to yourself."

The duckling repeated itself more vocally. Albus pursed his lips and nodded gravely.

"I'm afraid I can't fix this myself, Severus. It'll need to be done by a Metamorphmagus. Sadly, the only one I know is, undeniably, rather a klutz, but she is a natural at Transfiguration…"

Snape-The-Duck stared at the Headmaster in horror and said "Quaaaaa-wack-wack-wack?!"

"Yes, Tonks. Don't worry, Severus, you'll live." He thought for a second. "I hope."

In the background twenty pupils creased up silently.

The duckling staggered on its webbed little feet, blinked its black little eyes, and fell onto its feathery little back in a dead faint.

Fin.